The proposed work is designed to elucidate RNA metabolism as it is related to growth, development, and function of both normal and neoplastic cells. Emphasis will be placed on the study of RNA polymerase II and RNA polymerase III (C) (ribonucleoside triphosphate; RNA nucleotidyl-transferase (EC 2.7.7.6)), two of the three eukaryotic RNA polymerases. RNA polymerase II has been shown to be responsible for mRNA synthesis, while RNA polymerase III has been shown to be responsible for the synthesis of 5S RNA, tRNA, and 5.5S adenovirus associated RNA. Using enzyme purified from calf thymus and bovine lymphosarcoma, RNA synthesis will be studied using both DNA and chromatin templates. In vitro studies utilizing purified enzyme and template should furnish an insight into the relative roles of polymerase and the various components of chromatin in determining the specific transcription which occurs in vivo. Emphasis will be placed on transcription of histone genes by RNA polymerase II and transcription of the 5S RNA and tRNA genes by RNA polymerase III. Specific transcription will be monitored with plasmids containing the genes for histones, 5S RNA, and tRNA.